Control arrangement for copying devices



Spt. 2",1969 I s. KOLLESS CONTROL ARRANGEMENT FQR COPYING DEVICES FiledSept. 9. 1966 2 Sheets-Sheet 1 INVENTOR Sk /fled 52$ may J Jnkw ATTORNEY=$=rt-2- 4 5 m; 3 5.

. mind Sept]. 9. 1966 I con'rnox ARRANGEMENT FOR comm DEVICES 2Sheets-Sheet 2 INVENT OR ATTORNEY dam $140 United States Patent E Int.Cl. H05h 1/02 US. Cl. 219-216 18 Claims ABSTRACT OF THE DISCLOSURE Acontrol arrangement for copying devices of the type utilizing heat andlight for their copying function protects sensitive components of theapparatus against damage resulting from overheating. Cooling meansactuated by-a heat-responsive detector keep the temperature to which thecomponents are exposed within a predetermined range.

The present invention relates to a control arrangement. Morespecifically, the invention relates to a control arrangement for copyingdevices. Still more specifically, the invention relates to a controlarrangement for copying devices of the type utilizing heat and light fortheir copying function.

In copying devices which require the application of heat to material tobe copied, such material and also the material onto which the copy is tobe made are passed through a zone of radiated heat. Since it isessential that the material to be copied and the material on which thereproduction is to be made be in intimate contact when the actual imagetransfer takes place, the two materials are passed between two or moreco-operating rollers which press the materials together in face-to-facecontact. It is necessary for the materials to be heated precisely atthis time when they are pressed together by the rollers, and the heatingzone is therefore so arranged that the heating action coincides with thepassage of the materials between the rollers. In other words, theheating means provided for this purpose is intended to heat the papersduring the time of their passage between the rollers and it necessarilytherefore also heats the rollers at the same time.

The heat required for the process is such that, were the materials toremain stationary, they would be damaged by the heat. Since, however,the materials are in continuous movement 'between the rollers andtherebeyond such damage does not occur. The same considerations are truefor the rollers themselves which, if stationary, would also be damagedby the heat. Of course, While the materials are transported between therollers, the latter are in rotation 50 that no portion of theircircumference is subjected to prolonged influence of the heat. Tomitigate still further the influence of the heat on the rollers, whichconsist at least in part of rubber and/or similarly heat-susceptiblematerials, it is known to provide suitable cooling means for directing aflow of coolant, such as air, against the rollers.

Upon completion of the copying process, that is when the materials havepassed between the rollers and therebeyond, the source which radiatesthe heat is switched off, usually automatically. The rollers, which havealso completed their assigned function, can now be stopped. However, theintensity of heat radiated from the source does not immediately anddrastically decline but decreases only gradually. One is therefore facedwith the problem of protecting the rollers against localized overheatingwhile the heat intensity from the now non-operative source of heat isstill above a predetermined permissible level. In other words, if therollers were to be stopped as soon as the source of heat is switchedoff, those portions of the ice rollers exposed to the heat and locateddirectly in its path would very likely suffer highly undesirable damage.

It should be reiterated here that the rollers consist partly orcompletely of material which is susceptible to Such damage, for instancerubber, plastic, glass or similar materials, either individually or incombination. In particular it is very customary to dispose the source ofradiant heat, usually an elongated element, within a glass cylinder inaxial parallelism therewith. Obviously, such a cylinder cannot bestopped from rotating until its associated source of radiant heat hascooled oil? to the required degree.

Various efforts have been made to overcome this problem and anarrangement is known in which the source of heat energy is moved when ithas been switched off, so that the rollers are no longer directlyexposed to the emanating heat. Of course, such movement necessitates theprovision of additional relatively complicated features, such as a meansfor carrying out the movement, a timing arrangement for coordinatingsuch movement with the stopping of the rollers, and the like. Anotherarrangement proposes to connect the heat-sensitive detector inheatconducting relationship with a portion of the device which becomesheated during operation of the source, but is not directly disposed inthe path of the radiated heat. For instance, the suggestion has beenmade to connect such a heat-sensitive detector with a portion of thereflector which is generally used to focus the heat of the source, andto establish the connection with a portion of the reflector which is notdirectly located within the range of the impinging heat radiation. Thedisadavantage of this an rangement is that the detector will not operateit only a single copying episode or run is undertaken, that is if only asingle copy is to be made. The reason for this is that the reflectorwill not become heated uniformly and that the part located outside thedirect path of the radiant heat will during a single run not be heatedto a temperature which could cause the detector to operate. Conversely,after several copies have been made the reflector will become heatedthroughout and the heat-sensitive detector will then become constantlyactuated, which obviously is not desirable either. 7

It is therefore a general object of the present invention to provide acontrol arrangement which overcomes the above-mentioned disadvantages ofthe prior art.

A more specific object of the invention is to provide such a controlarrangement which will protect heatsensitive components of a copyingdevice reliably and accurately.

A further object of the invention is to provide such a controlarrangement which is simple to construct and therefore inexpensive.

A concomitant object of the invention is to provide such a controlarrangement which can be added, if desired, to existing copying devices.

Yet a further object of the invention is to provide such a controlarrangement which will maintain operation of a cooling means operativefor cooling heat sensitive components of a copying device, until theintensity of heat radiated by a source of heat has fallen below apredetermined level.

One important feature of my invention resides in the provision of acontrol arrangement which comprises a source of radiant heat, andheat-absorbing means positioned to receive heat from the source. Suchheat-absorbing means, it will be understood, incorporates the rollersbetween which the material to be copied and the material on which thecopy is to be made must pass. My novel control arrangement furtherincludes cooling means which is arranged for cooling the heat-absorbingmeans so as to preclude heating of the same beyond a predeterminedtemperature, and heat-responsive detector means which is positioned soas to be directly heated by heat radiated from the source. Thisheat-responsive detector means is operative for terminating theoperation of the cooling means upon a predetermined drop in thetemperature in the heat radiated by the source.

To assure accurate response by the detector means I prefer to providethe same adjacent a side of the source of radiant heat which is locatedremote from the material passing between the rollers. In other words,the paper will pass by the source to one side thereof and will therebybe heated, and the detector will be located at the opposite side. In afurther embodiment I contemplate positioning the detector completely orinpart either in an aperture provided in a reflector surrounding thesource of heat energy, or slightly spaced from the reflector but in linewith the aperture. Additionally, and to reduce the loss of radiated heatthrough this aperture, I contemplate providing the aperture as well asthe detector associated therewith at a location which is outside thepath of the material to be copied and the material on which the copy isto be produced. In other words, the source of heat energy will be madelonger than the axial extension of at least one of the rollers, and thislatter is a well-known expedient employed in the art in any case. Sincethe Width of copying material and material to be copied is determined bythe smallest axial length of the cooperating rollers it will be obviousthat, if the aperture is provided in a portion of the reflector whichprojects axially beyond the shorter roller, no heat energy which wouldotherwise be directed onto the copying material can be thereby lost.Nevertheless, the detector will be exposed to the direct heating actionof the source of heat, but only to the action of that part of the sourcewhich extends axially beyond the shorter of the rollers. As aheat-detector I prefer to use a bimetallic element whose response is soselected that its operating temperature at which it actuates the switchfor shutting off the cooling means will be reached on exposure to thedirect radiation of heat upon passage of only a single copy through thecopying device.

Various modifications of this basic arrangement are ofcourse possible,for instance, and just to mention one such possibility, I contemplate anarrangement wherein the insertion of the material to be copied and ofthe material on which the copy is to be made will automatically startall functions, with the source of heat energy being switched off as soonas the copying process is completed, and with the detector meanssubsequently shutting off all other functions of the machine when thetemperature inf the source of heat energy has dropped to the desiredevel.

In fact, the arrangement can be still further modified so that thedetector actuates the switch which automatically starts the drive meansand the cooling means when the materials are introduced into the copyingdevice.

The novel features which are considered as characteristic fortheinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 is a very schematic end view of an arrangement in accordance withthe present invention;

FIG. 2 is a fragmentary enlargement of the arrangement shown in FIG. 1;

FIG. 3 is a top plan view of an arrangement such as that shown in FIG.1;

FIG. 4 is a partially sectional view on an enlarged scale, showing thedetector means; and

FIG. 5 is a schematic view by way of illustrating the relative positionsof the rollers and the detector means.

Discussing now the drawing in detail, and firstly FIG. 1 thereof, itwill be seen that reference numeral 1 indicates a rotatable hollowcylinder of glass or another transparent material. FIG. 2 indicates apressure roller consisting wholly or partly of rubber. Reference numeral3 indicates two additional rollers which extend in axial parallelismwith the cylinder 1 and abut against the peripheral surface thereof. Itshould be understood that roller 2 is journalled for rotation as areboth of the rollers 3, whereas the cylinder 1 is loosely held by therollers 2 and 3 in a floating relationship. In other words, cylinder 1is not journalled. Only one of the rollers 3 need actually be driven andthe rollers 2 and 3 rotate in the direction of the respective arrowsassociated with them.

As is more clearly evident from FIG. 2 the cylinder 1 have disposedtherein in axial parallelism therewith a source 4 of radiant heatenergy. This source 4 is, as will be best seen from FIG. 3, of a lengthcorresponding or at least substantially corresponding to that of thecylinder 1. A reflector 5 surrounds the source 4 on one side thereof, sothat heat energy radiated by the source 4 is concentrated onto the pointat which cylinder 1 and roller 2 peripherally engage one another. It isbetween the cylinder 1 and the roller 2 that the material to be copiedand the material onto which the copy is to be made, both of which willfor the sake of simplicity hereafter be referred to as paper, must pass.The path of the paper is indicated with the arrow 9.

Reflector 5 is provided in the embodiment illustrated with a cutout oraperture 6 in which there is located a detector means 7 which, as isclearly evident from FIG. 4, comprises a substantially U-shapedbimetallic portion 7a which is secured to the reflector 5 by a screw orrivet 10, and one arm of which is secured to a rod portion 7b which inturn is connected to the switch 70. The lines indicated with referencenumeral 8 in FIGS. 2 and 4, show clearly that the detector means or atleast the temperature-sensitive portion 7a thereof is located directlyin the path of heat radiated by the source 4 towards the reflector 5, aportion of this heat passing through the opening 6 and impinging on thetemperature-sensitive portion 7a of the detector means 7.

FIG. 5 indicates how in the preferred embodiment of the invention theopening 6, through which direct radiated heat impinges on the detectormeans 7, is located outside the range in which the paper is to beheated. In other words, the opening 6 is located to one side of the path9. The width of this path 9 is indicated in FIG. 5 with referencenumeral 9a, and it will be obvious that the opening 6 is located to oneside of the path 9. The width of this path 9 is indicated in FIG. 5 withreference numeral 9a, and it will be obvious that the opening 6 islocated to one side of the area 9a, that is to one side as seen in axialdirection of the roller 2 and of the cylinder 1, which latter will beseen to be longer than the roller 2. This arrangement assures that theloss of heat energy which is useable for heating the area of the path 9is negligible inasmuch as the heat energy which is lost through theopening 6 with this arrangement would not ordinarily contribute to suchheating in any case.

FIG. 3, finally, is a top plan view of the entire apparatus utilizingthe arrangement in accordance with my present invention. Those elementswhich are identical with elements described heretofore are indicatedwith like reference numerals. It will additionally be seen that there isprovided a blower 11, which may be of the radial-flow type, fordirecting a stream of coolant onto the roller 2. The blower 11 is drivenby a separate drive 12 of any desired well-known type. The main drivemotor for the arrangement is indicated with reference numeral 13 andagain any well known motor will be suitable for this purpose. Carried bythe shaft of motor 13 is a cone structure 14 which engages a frictionwheel 15 and thus rotates the same. The friction wheel 15 in turncooperates with a gear-transmission 16 which drives a first pulley 17from whence a transmission belt 18 leads to a second pulley 19 rigidlyassociated with the driven roller 3, so that the latter is therebyrotated. The switch 70, it will be understood, is actuated by themovement of portion 7a, transmitted to it by the rod 7b, and it in turnswitches off the drive 12 for the blower 11 and the drive 13 for theroller 3 which actuates the roller 2 and the cylinder 1. Since theswitch 7:: is actuated only when the temperature of the heat emitted bythe source 7 has fallen below a predetermined level it will be clearthat the drives 12 and 13 continue to operate until this temperaturedrop has taken place, so that danger of localized or total over-heatingof the cylinder 1 and the roller 2 is thereby prevented.

The possibility of modifications has been pointed out earlier andseveral such modifications have been mentioned by way of example. Itmight be reiterated here that one such modification could be the use ofthe switch 70 for turning on the drives 12 and 13 upon insertion ofpaper into a copying device utilizing the novel control arrangement.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofcontrol arrangements, diifering from the types described above.

While the invention has been illustrated and described as embodied in acontrol arrangement, it is not intended to be limited to the detailsshown since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledgereadily adapt it for various applications without omitting features thatfrom the standpoint of prior art fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be secured by Letters Patent is:

1. A control arrangement comprising, in combination, a source of radiantheat; heat-absorbing means positioned to receive heat from said sourceand comprising a rotary element having a peripheral surface at leastpartly consisting of material subject to damage on heating beyond apredetermined temperature; cooling means arranged for cooling saidheat-absorbing means so as to preclude heating of the same beyond saidpredetermined temperature; and heat-responsive detector means positionedso as to be directly heated by heat radiated from said source andoperative for terminating operation of said cooling means in response toa predetermined drop in the temperature of the heat radiated by saidsource.

2. A control arrangement as defined in claim 1, wherein said coolingmeans includes drive means for rotating said rotary element whereby toelfect cooling of said rotary element through movement of the samerelative to the ambient atmosphere, and through preventing continuousexposure of any portion of said peripheral surface to the heat radiatedby said source.

3. A control arrangement as defined in claim 2, said cooling meansfurther including blower means arranged to direct a flow of gaseouscooling medium against said rotary element. 4

4. A control arrangement as defined in claim 1, wherein said coolingmeans includes blower means arranged to direct a flow of gaseous coolingmedium against said rotary element.

5. A control arrangement as defined in claim 1, wherein saidheat-responsive detector means comprises a bimetallic element.

6. A control arrangement as defined in claim 1, where in saidheat-absorbing means comprises a pair of axially parallel rotaryelements at least one of which has a peripheral surface at least partlyconsisting of material subject to damage on heating beyond saidpredetermined temperature.

7. A control arrangement as defined in claim 6, wherein one of saidrotary elements is a hollow cylinder, said source being at leastsubstantially arranged within said hollow cylinder.

8. A control arrangement as defined in claim 7, Wherein said material ofsaid hollow cylinder is transparent.

9. A control arrangement as defined in claim 7, wherein said source isan elongated heat radiating device extending axially parallel with saidhollow cylinder.

10. A control arrangement as defined in claim 9, wherein saidheat-radiating device comprises a heat-radiating member and a reflectorelement partly surrounding said member and directing heat radiatedthereby in direction toward the other of said rotary elements.

11. A control arrangement as defined in claim 10, wherein said reflectorelement is provided with a cutout, said detector means being at leastpartly located in alignment with said cut-out so as to be directlyheated by heat radiating from said heat-radiating member.

12. A control arrangement as defined in claim 11, wherein the peripheralsurfaces of said rotary members together define a path of a given width,as seen in axial direction of said rotary members, for passage of sheetmaterial between said members, said cut-out and said detector meansaligned therewith being located to one side of said path with referenceto the axial extension of said rotary members.

1'3. A control arrangement as defined in claim 11, wherein said detectormeans comprises a bimetallic element located in alignment with saidcut-out.

14. A control arrangement as defined in claim 13, wherein said detectormeans further comprises doubleacting switch means operatively connectedwith said bimetallic element, said switch means being operative foractuating said cooling means and for terminating operation of saidcooling means upon said drop in the temperature of the heat radiated bysaid source.

15. A control arrangement as defined in claim 11, wherein said coolingmeans comprises drive means operatively connected with at least one ofsaid rotary elements for driving the same.

16. A control arrangement as defined in claim 11, wherein saidperipheral surfaces of said rotary elements are in frictional engagementwith one another; said cooling means comprising drive means operativelyconnected with at least one of said rotary elements for driving the sameand thereby rotate both of said rotary elements.

17. A control arrangement as defined in claim 15, said cooling meansfurther comprising blower means arranged to direct a flow of gaseouscooling medium against the peripheral surface of at least one of saidrotary elements.

18. A control arrangement as defined in claim 17, said drive means andsaid -blower means being operatively connected for simultaneousoperation.

References Cited UNITED STATES PATENTS 2,501,495 3/1950 Carroll et al.10l-470 2,632,921 3/1953 Kreidl 117-38 3,156,812 11/1964 Forman et a1.2l9388 3,219,794 11/1965 Mindell et al. 219-388 X 3,228,382 1/ 1966Stefan -39 JOSEPH V. TRUHE, Primary Examiner C. L. ALBRITTON, AssistantExaminer U.S. Cl. X.R.

